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EP 0 242 935 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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04.09.1991 Bulletin 1991/36 |
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Date of filing: 14.01.1987 |
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Video signal motion detecting apparatus
Videosignal-Bewegungsdetektor
Appareil détecteur de mouvement d'un signal vidéo
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Designated Contracting States: |
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AT DE ES FR GB IT |
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Priority: |
17.01.1986 US 819861
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Date of publication of application: |
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28.10.1987 Bulletin 1987/44 |
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Proprietor: RCA LICENSING CORPORATION |
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Princeton
New Jersey 08540 (US) |
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Inventors: |
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- Weckenbrock, Hermann Johann
Bordentown
New Jersey (US)
- Roeder, Barbara Joan
Point Pleasant
Pennsylvania (US)
- Casey, Robert Francis
Oradell
New Jersey (US)
- Harwood, Leopold Albert
Bridgewater
New Jersey (US)
- Wedam, Werner Franz
Lawrenceville
New Jersey (US)
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Representative: Pratt, Richard Wilson et al |
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London Patent Operation
G.E. Technical Services Co. Inc.
Essex House
12/13 Essex Street London WC2R 3AA London WC2R 3AA (GB) |
(56) |
References cited: :
DE-A- 3 126 713 GB-A- 2 031 686 US-A- 4 352 126
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GB-A- 2 015 294 GB-A- 2 045 574 US-A- 4 361 853
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] This invention relates to apparatus for detecting time changes in images represented
by video signals.
[0002] Video signal processing circuitry such as field/frame comb filters, field/frame recursive
filters or progressive scan generators for example, have been designed which significantly
enhance the quality of images reproduced from video signals. These systems perform
very well for images which contain no motion (either image object motion or camera
panning). Conversely, when image motion does occur, such systems tend to introduce
undesirable artifacts. Consequently, these memory based processing systems are designed
to be motion adaptive, i.e. the systems are either altered or switched out of the
signal processing path when image motion occurs.
[0003] In order to alter motion adaptive systems during occurrences of image motion it is
necessary to detect such occurrences. Typical motion detectors known in the art of
video signal processing compare corresponding video signals from successive field
or frame intervals. The assumption is made that if the interfield/frame video signals
differ by more than a predetermined value motion has occurred.
[0004] Because video signals emanate from varying sources, e.g. different broadcast stations,
VCR's, they tend to have varying signal-to-noise ratios (SNR's). Differences in SNR's
complicates designing motion detectors to discriminate between image motion and image
noise. One approach to discriminating between noise and motion is to average a number
of signal differences corresponding to pixels surrounding the picture point being
examined. Noise being uncorrelated, will tend to cancel. Signal differences corresponding
to image object motion for localized pixels tend to exhibit a degree of correlation
and thus add constructively.
[0005] The signal differences that are averaged are selected to correspond to pixels that
are symmetrically disposed horizontally, vertically or both about the pixel being
examined. Some systems weight the signal differences being averaged so that the signal
averages exhibit a low-pass response.
[0006] Motion detectors are known which examine field/frame differences to determine the
occurrence of motion are designed to operate on component rather than composite video
signals. The reason for this is that chrominance components of composite video signals
do not have similar phase relationships from frame-to-frame. Inherent frame-to-frame
chrominance differences will produce motion signals even for still images. In order
to preclude false motion detection when successive frames of composite video signal
are compared, the composite video signal is typically limited to the low frequency
luminance spectrum before comparison.
[0007] Examining only the low frequency spectrum of interframe composite video signal differences
for motion, tends not to be satisfactory. In this instance motion of fine image detail
cannot be detected. As an example, movement of a person's hair will not be detected
in the reproduced image regardless of the speed of motion. Failure to detect motion
of fine detail will generally tend to result in a blurred image.
[0008] Motion detectors are known which do operate on composite video and a) separate the
luminance and chrominance components, b) align the phase of the corresponding frame-to-frame
chrominance components, c) recombine the phase altered chrominance component with
the luminance component and d) take the interframe difference of the composite and
chrominance phase altered composite video signals. This approach to detecting motion
in composite video signals is not satisfactory because luminance and chrominance components
cannot be completely separated in the chrominance spectrum of the composite video
signal. The unseparated or residual luminance component in the separated chrominance
signal undergoes an alteration during the chrominance phase alignment process. When
this altered high frequency luminance is recombined and the interframe signal differences
are taken, signal differences may occur in the absence of motion resulting in false
motion detection.
[0009] GB-A-2O45 574 discloses a video movement detection apparatus suitable for detecting
picture movement and/or noise on a video signal. The apparatus comprises a first detector
for detecting differences frame by frame on a portion of picture having a plurality
of picture points from more than one line, a second detector for detecting differences
frame by frame from a portion of picture having a plurality of picture points from
the same line, and a third detector for detecting differences frame by frame from
a portion of a picture comprising a single picture point. Movement is determined to
have taken place when the differences measured by the respective detectors exceed
predetermined thresholds. The selected thresholds are typically of different values
to provide the capability of distinguishing between noise and movement in varying
conditions.
[0010] The present invention seeks to provide detection of motion in a video signal with
a minimum of false detection signals due to noise and cross components.
[0011] According to the present invention there is provided a signal interimage motion detector
comprising:
a signal interimage motion detector comprising an input terminal (CV) for receiving
a video signal; and means coupled to said input terminal for providing differences
between video signals from successive image periods; characterized by first means,
coupled to said means for providing differences, for summing a plurality of said differences,
said plurality of differences including a difference corresponding to an image point
currently under examination for interimage motion, and differences corresponding to
image points proximate said image point under examination occurring in a horizontal
image line containing said image point under examination and in a preceding horizontal
image line to produce first summed differences; second means, coupled to said means
for providing differences, for summing a plurality of said differences, said plurality
of differences including a difference corresponding to said image point under examination,
and differences corresponding to image points proximate said image point under examination
occurring in said horizontal image line containing said image point under examination
and in a succeeding horizontal image line to produce second summed differences; and
means coupled to said first and second summing means, for producing a motion signal
whenever said first and second summed differences concurrently exceed a predetermined
magnitude value.
[0012] For a better understanding of the present invention, reference will now be made,
by way of example, to the accompanying drawings, in which:-
FIGURE 1 is a block diagram of a motion detector including apparatus to detect motion
in composite video signal.
FIGURE 2 is a partial block, partial schematic diagram of a detector for detecting
motion represented by interimage changes in the luminance component of composite video
signals.
FIGURE 3 is a chart of composite signal samples corresponding to portions of two frames
of video information and the sample differences between the two frames of information.
FIGURE 4 is a partial block, partial schematic diagram of an embodiment of the FIGURE
2 motion detector shown in greater detail.
FIGURE 5 is a block diagram of a detector for detecting motion represented by interimage
changes in the chrominance component of composite video signals and FIGURE 6 is a
more detailed schematic diagram of one embodiment of the detector illustrated in FIGURE
5.
[0013] In the following description the assumption is made that the composite video signal
applied to the motion detecting apparatus is in sampled data format. For purposes
of illustration, the sample rate is selected to be four times the color subcarrier
rate and phase locked to color burst, though other sample rates may be selected. In
the diagrams, the elements are illustrated in functional terms which are applicable
to both analog and digital signal processing environments since the invention may
be practiced with either analog or digital circuits. All of the individual circuit
elements, both digital and analog, are well known in the art of video signal processing,
and, thus, will not be described in detail. Depending on the choice of processing
circuitry it may be necessary to include compensating signal delay elements to align
in time signals in the different circuit paths, but one skilled in the art of circuit
design will readily comprehend and include such delays.
[0014] Referring to FIGURE 1, composite video (CV) signal which may be supplied from a television
tuner in a TV receiver environment, from a color camera, or from the signal pickup
circuitry in a VCR environment etc. is applied to delay element 10, a luminance motion
detector 12 and a chrominance motion detector 14. Delayed signal from delay element
10 is coupled to respective second input connections of detectors 12 and 14. For NTSC
composite video signals, delay element 10 will typically delay the applied signal
CV by precisely one frame interval. For PAL composite video signal delay element 10
may delay the signal CV by two frame intervals.
[0015] Luminance motion detector 12 compares the current and delayed video luminance component
of the composite video signals and generates a motion signal (LM) if a predetermined
difference exits between the two luminance signals. Chrominance motion detector 14
compares the current and delayed chrominance components of the composite video signals
and generates a motion signal (CM) if a predetermined difference exists between the
two chrominance signals. The motion signals LM and CM from detectors 12 and 14 are
coupled to respective inputs of an OR gate 16 which develops a motion signal when
either the luminance or chrominance motion detectors generate a motion signal.
[0016] FIGURE 2 illustrates one embodiment of a luminance signal motion detector which may
be implemented as motion detector 12 in FIGURE 1. In FIGURE 2 the current and delayed
composite video signals are coupled to respective input terminals of the subtracter
20. Subtracter 20 develops frame difference samples which are coupled to the input
terminals of a low-pass filter 22 and a high-pass filter 24. Low-pass filter 22 passes
that portion of the composite video signal frequency spectrum not normally occupied
by the chrominance component. Conversely, high-pass filter 24 (which may be a bandpass
filter) passes that portion of the composite video signal spectrum which is normally
occupied by the chrominance component.
[0017] The signal differences provided by low-pass filter 22 are coupled to a signal combining
element 26. Combining element 26 sums a number of the frame difference samples. Element
26 is drawn as a matrix of three rows with three squares in each row. Each of the
squares represents a signal difference sample. The central square corresponds to the
image point or sample under examination for image motion. The square to the left and
right of the central box correspond to sample differences occurring on the same horizontal
image line. However, it is to be understood that these two sample differences need
not correspond to the immediately preceding and succeeding sample differences in the
stream of sample differences occurring at the four-times color subcarrier rate. The
squares in the rows above and below the middle row correspond to sample differences
from horizontal image lines occurring before and after the image line containing the
pixel under examination. The cross hatching is intended to illustrate that each of
the sample differences represented by the squares in the illustrative 3x3 matrix contribute
to the sum generated by combining element 26.
[0018] The sum produced by element 26 is applied to a threshold detector 28. Threshold detector
28 provides a logic one output signal for the condition that the sum exceeds a predetermined
magnitude and a logic zero otherwise. A digital embodiment of the threshold detector
28 may comprise the cascade connection of an absolute value circuit and an N-input
OR gate. The absolute value circuit is configured to convert all sums to a single
polarity signal. If the output signal of the absolute value circuit is a parallel
N-bit signal, the M more significant bits are coupled to the M more significant input
connection of the N-input OR gate. The N-M lesser significant bit connections of the
OR gate are coupled to a logic zero signal. In such a configuration the OR gate will
develop a logic one output signal for sums having magnitudes exceeding the values
(2
N-M-1).
[0019] The output signal of the threshold detector 28 is coupled to one input connection
of the two-input OR gate 40.
[0020] The output signal from the high-pass filter 24 is coupled to two signal combining
circuits 30 and 34. Combining circuit 30 combines sample differences from the horizontal
image line containing the pixel under examination and a horizontal image line preceding
the image line containing the pixel under examination. The central square in the illustrative
matrix corresponds to the pixel under examination. The cross hatching indicates the
samples that are combined by element 30. The samples that are combined from the two
lines are vertically aligned relative to the displayed image. The preceding line is
selected such that the vertically aligned samples have an antiphase color subcarrier
relationship. For example, if the composite video signal is an NTSC signal the preceding
line is the immediately preceding image line, or the third, fifth, etc. most immediate
preceding line. The difference samples to the right and left of the difference sample
corresponding to the pixel under examination need not be the difference samples immediately
preceding and following the control difference sample.
[0021] The output of the combining element 30 is coupled to a threshold detector 32 which
develops a logic one output signal for the condition that the combined difference
samples exceed a predetermined magnitude and a logic zero otherwise. The output signal
from threshold detector 32 is coupled to one input connection of a two input AND gate
38.
[0022] Combining element 34 is similar to combining element 30 except that it combines sample
differences from the horizontal image line containing the difference sample corresponding
to the pixel under examination with difference samples from a horizontal image line
occurring later in time. The combined difference samples from combining element 34
are coupled to a threshold detector 36 which functions similarly to threshold detector
32. The output signal from threshold detector 36 is coupled to a second input connection
of the AND gate 38.
[0023] AND gate 38 produces a logic one output signal only when both threshold detectors
32 and 36 concurrently produce logic one output signals. The output signal from AND
gate 38 is coupled to a second input connection of OR gate 40. OR gate 40 produces
a logic one output signal, indicating image motion, whenever threshold detector 28
or AND gate 38 output logic one signals.
[0024] In the FIGURE 2 arrangement, elements 22, 26 and 28 detect image motion represented
by luminance signal defining coarse image object detail. Elements 24, 30-38 detect
image motion represented by luminance signal defining fine image object detail. For
fine detail motion detection, parallel combining-circuit-threshold-detection circuits
are incorporated to preclude false motion detection resulting from particular image
chrominance transitions as will be explained with reference to FIGURE 3.
[0025] The threshold values selected for threshold detectors 28, 32 and 36 may be fixed
constants or made variable as a function of signal-to-noise ratio (SNR) as is known
in the art of e.g. video signal recursive filters. Typically threshold detectors 32
and 36 will be designed to respond to like threshold values. Threshold detector 28
in general will require a dissimilar threshold value because a) combining element
26 combines a larger number of difference samples than elements 30 and 34, and b)
the difference samples combined by element 26 contains less cross components than
the difference samples combined by elements 30 and 34.
[0026] Shown in FIGURE 3 are corresponding samples from portions of three successive horizontal
image lines of two successive frames of NTSC composite video. The samples occur in
conformance to a four times subcarrier sampling rate phase locked to the subcarrier.
Y
ij values correspond to the luminance component. The ±I
ij and ±Q
ij values correspond to quadrature related chrominance components wherein the ± signs
designate sampling phase and not necessarily sample polarity. In general successive
I values along a horizontal line have substantially equal magnitude and are of opposite
polarity. Similarly successive Q values have substantially equal magnitudes and are
of opposite polarity. Due to the relatively high redundancy of video signal information
vertically aligned samples from line-to-line represent like picture information.
[0027] The frame-to-frame sample differences, as developed by e.g. subtracter 20 in FIGURE
2 are also illustrated. The ΔY
ij terms represent the luminance differences and the ±(I
ij+I′
ij) and ±(Q
ij+Q′
ij) terms represent chrominance sample differences. In FIGURE 2 the low-pass filter
22 attenuates the ±(I
ij+I′
ij) and ±(Q
ij+Q′
ij) terms so that combining circuit only operates on lower frequency ΔY
ij luminance differences. If no image changes occur between frames, the values ΔY
ij will be zero except for noise contributions, i.e. electrical noise or quantization
noise. Due to the random nature of noise, summing a number of the ΔY
ij terms as in combining element 26 will tend to average the noise contribution to zero.
Thresholding the sums in detector 28 is performed to add a further degree of noise
immunity. Disregarding noise, if interframe image changes occur, a number of the ΔY
ij samples will be non zero. This is so even for slight image changes because the signal
is over sampled. Thus, summing a number of ΔY
ij values in the vicinity of the pixel under examination will produce a larger motion
signal than examining a single pixel difference sample. The SNR of the motion signal
is therefore significantly enhanced.
[0028] The sample differences applied to combining elements 30 and 34 contain both high
frequency luminance differences and chrominance information. Note that for NTSC signals,
frame-to-frame chrominance components are antiphasal. Subtracting the interframe chrominance
components has the effect of summing them as indicated in the matrix of difference
sample values.
[0029] Due to the relatively high line-to-line redundancy of video images, and to the line-to-line
antiphasal relationship of the chrominance component, summing vertically aligned difference
samples from two adjacent lines will tend to cancel the chrominance components of
the difference samples, leaving the high frequency luminance differences ΔY
ij.
[0030] Combining element 30 sums the difference samples from e.g. lines l and 2 shown in
FIGURE 3, and combining element 34 sums the difference samples from e.g. lines 2 and
3 shown in FIGURE 3.
[0031] If the pixel under examination corresponds to a difference sample in line 2 either
the sum from combining element 30 or 34 may indicate high frequency luminance motion.
The parallel detectors (30-32) and (34-36) are incorporated to preclude false motion
detection. Images occur wherein from line-to-line there may be a chrominance transition
from one color to a different color or a transition from a colored image to a black
and white image. For either of these conditions summing the line-to-line difference
samples will not cancel the chrominance component resulting in a false detection.
However, it is extremely unlikely that such a condition will concurrently occur between
both the pair of lines 1 and 2 and the pair of lines 2 and 3. Therefore, if one, but
not both, of detectors (30-32) and (34-36) generate a motion signal, one of these
special image conditions, and not motion, is the cause. To preclude false detection,
the two detectors are ANDED together. In effect detector (30-32) in conjunction with
the AND gate 38 monitors detector (34-36) for such false motion detection and vice
versa.
[0032] The effect of chrominance transitions causing false detection may be reduced further
by judicious selection and weighting of the difference samples combined in elements
30 and 34. Let the difference samples be designated S
ij where the indices correspond to the indices of the ΔY
ij components in FIGURE 3. Further, let the difference sample S₂₃ correspond to the
pixel under examination. A combining element 30 which combines samples S₁₁, S₂₁, S₁₅,
S₂₅ in a ratio of 1:2 with samples S₁₃ and S₂₃ will be significantly less sensitive
to vertical chrominance transitions because the weighting tends to structure the combining
circuitry to perform notch filtering at the chrominance subcarrier frequency. Combining
element 34 will be similarly designed to sum the difference samples S₂₁, S₃₁, S₂₅,
S₃₅ in the ratio of 1:2 with the difference samples S₂₃ and S₃₃.
[0033] FIGURE 4 shows circuitry for realizing this latter embodiment. In FIGURE 4 the low-pass
filtered difference samples from filter 22 are coupled to two cascade connected delay
elements 52 and 54 and to one input connection of a sample summing circuit 56. Delay
elements 52 and 54 each provide a like delay interval of an integral number of sample
periods e.g. one, two or three sample periods. Delayed difference samples from delay
elements 52 and 54 are coupled to respective second and third input connections of
summing circuit 56. Summing circuit 56 produces difference sample sums, S, of three
difference samples from the same horizontal image line, which may be described by
the equation
[0034] The difference sample sums from summing circuit 56 are coupled to the cascade connection
of two one-horizontal-line delay elements 58 and 60. The output signals from summing
circuit 56, delay element 58 and delay element 60 are coupled to respective input
connections of summing circuit 62 and represent sample sums from three horizontal
image lines. Summing circuit 62 produces a difference sample sum of three difference
samples from each of three successive lines. This sample sum is coupled to the threshold
detector 64 which corresponds to the threshold detector 28 in FIGURE 2. The output
signal from threshold detector 64 corresponds to a low frequency luminance motion
signal and is coupled to an input connection of OR gate 86.
[0035] The difference samples from the subtracter 20 are coupled to the minuend input connection
of subtracter 50 and the low-pass filtered difference samples from filter 22 are coupled
to the subtrahend input connection of subtracter 50. The frequency spectrum exhibited
by the signal output from subtracter 50 is complementary to the signal spectrum of
the signal output from the low-pass filter 22. In other words the combination of subtracter
50 and low-pass filter 22 forms a high-pass filter with respect to the composite video
signal spectrum.
[0036] High-pass filtered difference samples from subtracter 50 are coupled to the cascade
connection of the two delay elements 66 and 68. In this particular embodiment delay
elements 66 and 68 each provide signal delays of two sample periods. In consequence,
delay elements 68 and 66 and the input of delay element 66, provide every second sample
difference i.e. S
i1, S
i3 and S
i5. The output connection of subtracter 50, delay element 66 and delay element 68 are
coupled to respective input connections of weighting and combining circuit 70. The
outer difference samples S
i1 and S
i5 are weighted by one-half and summed with the difference sample S
i3, to form the weighted sum of three sample differences from one horizontal image line.
[0037] The weighted sums from weighting and combining circuit 70 are coupled to the cascade
connection of the two one-horizontal-line delay elements 72 and 74. The input and
output connections of delay element 72 are coupled to respective input connections
of adder 76. Adder 76 produces difference sample sums which correspond to the sums
produced by combining element 30 in FIGURE 2. The input and output connections of
delay element 74 are coupled to respective input connections of a further adder 78.
Adder 78 produces difference sample sums corresponding to the output sums provided
by combining element 34 of FIGURE 2.
[0038] The output sums provided by adders 76 and 78 are coupled to threshold detectors 80
and 82 respectively. The output connections of threshold detectors 80 and 82 are coupled
to respective input connections of the two-input AND gate 84, the output of which
is coupled to the second input connection of OR gate 86.
[0039] In the circuitry of FIGURES 2 and 4 the full band signal differences may be applied
directly to the high frequency detectors, i.e. (30-32) and (34-36), and the low frequency
detector (26-28) omitted. The advantage of this arrangement is a reduction in hardware.
The disadvantage is a small penalty in terms of motion/noise discrimination because
the low frequency detector (26-28) exhibits a better motion/noise ratio due to the
symmetry of differences selected.
[0040] FIGURE 5 illustrates a detector for detecting inter-image motion represented by the
chrominance component of composite video signal and which may be used for the motion
detector 14 in FIGURE 1. In FIGURE 5, current composite video signal samples and corresponding
frame delayed composite video samples are coupled to respective input connections
of an adder 90. If there are no inter-image changes, adder 90 will produce sample
sums corresponding to 2Y
ij. The chrominance components being antiphase from frame-to-frame cancel in the summing
process. Conversely, if there is inter-image motion the sums output by adder 90 will
correspond to 2Y
ij+ΔY
ij±ΔI
ij or to 2Y
ij+ΔY
ij±ΔQ
ij, where ΔY
ij is the image change represented by the luminance component and ±ΔI
ij and ±ΔQ
ij are image changes represented by the quadrature related chrominance components. The
chrominance changes ΔI
ij and ΔQ
ij alternate in polarity at the subcarrier rate and thus are designated ±ΔI and ±ΔQ.
The changes ΔI
ij and ΔQ
ij will tend substantially to be antiphasal from line-to-line (NTSC) and antiphasal
every two lines for PAL signals.
[0041] The sample sums produced by adder 90 are applied to a filter 92 which attenuates
samples having frequencies outside the band of frequencies normally occupied by the
chrominance component of composite video signal. The filtered sample sums are coupled
to sample combining circuits 94 and 96.
[0042] Combining element 94 combines sample sums from the horizontal image line containing
the sample sum representing the current pixel under examination and sample sums from
a previously occurring horizontal image line. Combining element 96 combines sample
sums from the horizontal image line containing the sample sum, representing the pixel
under examination and sample sums from a succeeding horizontal image line. All of
the sample sums combined by either element 94 or 96 are in relatively close proximity
to the sample sum representing the pixel under examination though not necessarily
immediately adjacent. Combining elements 94 and 96 are represented by like matrixes
of three rows of three squares per row.
[0043] Each row represents a portion of sample sums from one image line. Each square represents
a sample sum. However, only the sample sums represented by a square containing a plus
or a minus sign are included in combined samples produced by combining elements 94
and 96. In addition, the plus and minus signs designate the polarity with which each
of the sample sums are combined. The sample sums of each vertically aligned pair of
sums are combined with opposite polarity. Because of the high line-to-line redundancy
of most images the luminance components in the vertically aligned sample sums will
cancel. The polarity selection by which the sample sums are combined also tend to
render the chrominance component differences to a single like polarity so that all
non zero chrominance differences sum constructively to produce a motion signal with
enhanced SNR.
[0044] The combined sample sums generated by combining circuits 94 and 96 are applied to
respective threshold circuits 98 and 100. Threshold circuits 98 and 100 develop logic
one output signals if the signal applied to its respective input connection exceeds
a predetermined value and develop logic zeroes otherwise. The output connection of
threshold circuits 98 and 100 are coupled to respective input connections of the two-input
AND gate 102. AND gate 102 produces a logic one output signal, indicating image motion,
only when both of the threshold circuits 98 and 100 concurrently produce logic one
output signals.
[0045] The chrominance motion detector utilizes parallel detectors (94,98) and (96,100)
to preclude false motion detection resulting from line-to-line or vertical luminance
transitions which would defeat luminance cancellation in either one or the other of
the combining circuits. It is very unlikely that such a luminance transition will
occur between the two lines from which samples are combined by circuit 94 and concurrently
between the two lines from which samples are combined by circuit 96. Thus, for line-to-line
luminance transitions not due to image motion, only one of the detectors (94,98) or
(96,100) will develop a motion signal, which is insufficient to condition AND gate
102 to produce a chrominance motion signal. However, it is certain that if motion
occurs at pixels represented by the squares in the middle row of sample sums, which
row contains the pixel under examination, both detectors 94 and 96 will simultaneously
detect such occurrence. In this instance AND gate 102 will be conditioned to provide
a chrominance motion signal.
[0046] FIGURE 6 shows one embodiment of the FIGURE 5 motion detector in greater detail.
In FIGURE 6, elements designated with like numerals to those in FIGURE 5 perform like
functions.
[0047] In FIGURE 6 the high-pass filtered sample sums from filter 92 are coupled to the
cascade connection of two similar delay elements 110 and 112. Delay elements 110 and
112 each delay the sample sums by a small number of sample periods. It is advantageous
that delay elements 110 and 112 be designed to delay samples by two sample periods
to ensure more complete luminance cancellation. This result arises by virtue of including
only one of the quadrature chrominance components (e.g. the ΔI
ij component) in the combined sample sums.
[0048] The sample sums from the filter 92 and the twice delayed sample sums from delay element
112 are coupled to non-inverting input connections of the summing circuit 114. The
delayed sample sums from delay element 110 are coupled to an inverting input connection
of summing circuit 114. Circuit 114 develops the sum of the sample sums applied to
its non-inverting input connections and the negative of the sample sums applied to
its inverting input connection, which sums correspond to the sums of sample sums along
one horizontal image line. Note that the inverting and non-inverting inputs may be
interchanged without altering the system function. In addition, more than three sample
sums per horizontal line may be combined. Finally, the sample sums may be weighted
as in the FIGURE 4 circuitry.
[0049] The combined sums from the summing circuit 114 are coupled to the cascade connection
of two one-horizontal-line delay elements 116 and 118. Delayed combined sums occurring
at the output connections of delay element 118 correspond to the combination of sample
sums from the top row of squares in the matrix of elements 94 and 96 in FIGURE 5.
The output connections of delay element 116 provides combined sums corresponding to
the combination of sample sums represented by the middle row of squares in the matrix
of elements 94 and 96 in FIGURE 5, and the output connection of combining element
114 provides combined sums corresponding to the combination of sample sums represented
by the bottom row of squares in the matrix elements 94 and 96.
[0050] The combined sums from the output connections of delay elements 116 and 118 are applied
to the subtrahend and minuend input connections of subtracter 122 respectively. Substracter
122 combines the combined sums in accordance with the respective sample sum polarities
indicated in the matrix of element 94. The output of subtracter 122 is threshold detected
in threshold circuit 98, the output of which in coupled to one input connection of
AND gate 102.
[0051] The combined sum from the output connections of combining element 114 and delay element
116 are coupled to the minuend and subtrahend input connections respectively of subtracter
120. Subtracter 120 combines the combined sums in accordance with the respective sample
sum polarities indicated in the matrix of element 96 of FIGURE 5. The combined sums
produced by subtracter 120 are threshold detected in threshold circuit 100, the output
of which is coupled to a second input connection of AND gate 102. AND gate 102 develops
a chrominance motion, signal on the condition that the combined sums from subtracters
120 and 122 concurrently exceed a predetermined threshold value.
[0052] In the foregoing embodiments the circuitry initially combines sample sums occurring
in respective horizontal lines and then combines the combined samples from the respective
horizontal lines. It will be appreciated by those skilled in the art of signal processing
that sample sums from the different horizontal lines may be combined first, and then
these combined sums combined horizontally. A further alternative embodiment may provide
all of the sample sums and/or difference signals of the respective matrices simultaneously,
which samples may then be combined in a tree arrangement of adders/subtractors.
[0053] The illustrative embodiments imply that the motion indicating output signals are
single bit bilevel signals. It will be appreciated by those skilled in the art that
the motion indicating signals may be multi-bit signals which may correspond, for example,
to the average of the combined samples produced by the respective combining means,
or the differences between the combined samples and the appropriate threshold values
etc.
1. A signal interimage motion detector comprising:
an input terminal (CV) for receiving a video signal; and
means (10,20) coupled to said input terminal for providing differences between
video signals from successive image periods;
characterized by first means (30), coupled to said means for providing differences,
for summing a plurality of said differences, said plurality of differences including
a difference corresponding to an image point currently under examination for interimage
motion, and differences corresponding to image points proximate said image point under
examination occurring in a horizontal image line containing said image point under
examination and in a preceding horizontal image line to produce first summed differences;
second means (34), coupled to said means for providing differences, for summing
a plurality of said differences, said plurality of differences including a difference
corresponding to said image point under examination, and differences corresponding
to image points proximate said image point under examination occurring in said horizontal
image line containing said image point under examination and in a succeeding horizontal
image line to produce second summed differences; and
means (32,36,38), coupled to said first and second summing means, for producing
a motion signal whenever said first and second summed differences concurrently exceed
a predetermined magnitude value.
2. A detector according to claim 1 for detecting interimage motion in images represented
by a composite video signal wherein:
the input terminal (CV) is for receiving the composite video signal (CV);
the providing means (10,20) comprises delay means (10), coupled to said input terminal,
for providing replicas of said composite video signal delayed by an integral number,
including one, of image periods and means (20) coupled to said input terminal and
said delay means for providing differences of said composite video signal and said
delayed composite video signal;
and further comprising means (24), including means coupled to said providing means
(20), for passing to a first output terminal differences having frequency components
normally occupied by chrominance components of said composite video signal to the
relative exclusion of other frequency components of said composite video signal;
and wherein the said first and second means (30,34) are coupled to said first output
terminal;
and the motion signal producing means comprises a first threshold detector (32),
coupled to said first means, for producing a motion indicating signal when summed
differences applied thereto exceed a predetermined magnitude
a second threshold detector (36), coupled to said second means, for producing a
motion indicating signal when summed differences applied thereto exceed a predetermined
magnitude, and
means (38,84), coupled to said first and second threshold detectors for providing,
at a second output terminal, a motion indicating signal whenever the first and second
threshold detectors concurrently produce motion indicating signals.
3. A detector according to Claim 2 which, further includes:
means (22), coupled to said means (20) for providing differences, for passing to
a third output terminal, differences having frequency components of said composite
video signal not normally occurring in the frequency spectrum occupied by said chrominance
component;
third means (26,56,62), coupled to said third output terminal, for summing a plurality
of said differences, said plurality of differences corresponding to image points symmetrically
disposed about said image point under examination;
a third threshold detector (28,64), coupled to said third means, for producing
a motion indicating signal when summed differences applied thereto exceed a predetermined
magnitude; and
means (40,86) coupled to said third threshold detector and said second output terminal
for providing at a fourth output terminal a motion indicating signal whenever said
third threshold detector or said second output terminal produce a motion indicating
signal.
4. A detector according to Claim 3 wherein said differences occur as sampled data differences
and said third means (26) comprises:
a cascade connection of
means (56) for summing a plurality of sample differences corresponding to image
points occurring in one horizontal image line and
means (62) for summing summed sample differences corresponding to image points
occurring in successive horizontal image lines.
5. A detector according to any one of claims 2 to 4 wherein said differences occur as
sampled data differences and said first means (30) includes:
first summing means (70) coupled to said first output terminal for summing difference
samples corresponding to image points occurring in the same horizontal image line;
and
second summing means (78) coupled to said first summing means, for summing summed
difference samples provided by said first summing means from two different horizontal
image lines; and
wherein said second means (34) includes means (76) coupled to said first summing
means (70), for summing summed difference samples provided by said first summing means
from two horizontal image lines one of which is different from the horizontal image
lines summed by said second summing means.
6. A detector according to any one of claims 2 to 5 further comprising:
means (90) coupled to said input terminal and said delay means (10) for providing
sums of said composite video signal and said delayed composite video signal;
filter means (92), coupled to said means (90) for providing sums, for passing frequency
components of said sums normally occurring in the frequency band of composite video
signal occupied by chrominance components;
first additional means (94,114,122), coupled to said filter means (92) for summing
a plurality, even in number, of said sums, said plurality of sums corresponding to
image points occurring in a horizontal line containing said image point under examination
and image points occurring in a horizontal image line preceding said horizontal image
line containing said image point under examination, said first additional means (94,114,122)
summing alternate sums along a horizontal image line in opposite polarity and wherein
one half of said plurality of sums are in a positive polarity sense and one half of
said plurality of sums are in a negative polarity sense;
a first additional threshold detector (98), coupled to said first additional means
(94,114,122), for producing a motion indicating signal whenever summed signals provided
by said first combining means exceed a predetermined magnitude;
second additional means (96,114,120), coupled to said filter means (92), for summing
a plurality, even in number, of said sums, said plurality of sums corresponding to
image points occurring in said horizontal line containing said image point under examination
and image points occurring in a horizontal image line following said horizontal image
line containing said image point under examination, said second additional means (96,114,120)
summing alternate sums along a horizontal image line in opposite polarity and wherein
one half of said plurality of sums are summed in a positive polarity sense and one
half of said polarity sum are summed in a negative polarity sense;
a second additional threshold detector (100), coupled to said second additional
means (96,114,120), for producing a motion indicating signal whenever summed signals
provided by said second additional means exceed a predetermined magnitude;
means (102) coupled to said first additional and second additional threshold detectors
for providing a chrominance motion indicating signal when said first additional and
second additional threshold detectors concurrently provide motion indicating signals.
7. A detector according to Claim 6 which further includes means (16) responsive to said
chrominance motion indicating signal and said motion indicating signal provided by
said second output terminal for providing a motion indicating signal on the occurrence
of said chrominance motion indicating signal or said motion indicating signal provided
at said second output terminal.
8. A detector according to Claim 6 or Claim 7 wherein said sums occur as sampled data
sums and said first additional means (94) includes:
a cascade connection of first and second delay elements (110,112) coupled to said
filter (92) for providing delayed replicas of said sums, said first and second delay
elements each providing like delays of an integral number of sample periods;
means (114) coupled to said filter (92) and said second delay element (112) for
summing said sum samples from said filter and twice delayed sum samples rrom said
second delay element in opposite polarity sense with once delayed sum samples from
said first delay element (110) to produce horizontally summed sum samples;
a further delay means (118) coupled to said means (114) for producing horizontally
summed sum samples, said further delay means (118) providing sample delays of one
horizontal image line period; and
a further means (122) coupled to an input and an output of said further delay means
(118) for summing said horizontally summed sum samples in opposite polarity.
9. A detector according to any one of Claims 6 to 8 in which said preceding horizontal
image line is selected such that chrominance components therein have an antiphase
relationship with chrominance components corresponding to said horizontal image line
containing said image point under examination.
10. A detector according to claim 1 for detecting composite signal interimage motion,
wherein the input terminal is for receiving the composite video signal (CV);
the providing means (20,24) provides said differences as interimage difference
samples, of corresponding signals from two image periods, from frequency components
of said composite video signal containing fine luminance image detail information;
and the motion signal producing means (32,36,38) is coupled to said first and second
combining means, for producing a fine detail luminance motion signal whenever said
first and second summed difference samples concurrently exceed a predetermined magnitude
value.
11. detector according to Claim 10 further comprising
means (20,22) coupled to said input terminal for producing interimage difference
samples from frequency components of said composite video signal representing coarse
luminance image detail information;
a third means (26) for summing a plurality of difference samples representing coarse
luminance detail information to produce third summed difference samples, said plurality
of difference samples representing coarse luminance detail information corresponding
to image points proximate said image point under examination; and
means (28) coupled to said third means, for producing a coarse detail luminance
motion indicating signal whenever said third summed difference samples exceed a predetermined
magnitude.
12. A detector according to Claim 11 further comprising means (40) responsive to said
fine detail luminance motion indicating signal and said coarse detail luminance motion
indicating signal for developing a luminance motion indicating signal whenever either
of said fine or coarse detail luminance motion indicating signals indicate motion.
13. A detector according to any one of claims 10 to 12 further comprising
means (90,92) coupled to said input terminal for producing interimage sample sums
of corresponding signals from two image periods, from frequency components of said
composite video signal containing chrominance components
to the substantial exclusion of other frequency components of composite video signal;
first means (94) coupled to the means for producing sample sums, for combining
a plurality of sample sums selected from sample sums corresponding to image points
occurring in said horizontal image line containing said image point under examination
and a preceding horizontal image line, wherein alternate sample sums from a horizontal
image line are combined in opposite polarity sense and one half of said plurality
of sample sums are combined in a positive polarity sense and one half in a negative
polarity sense to produce first combined samples sums;
second means (96) coupled to the means for producing sample sums for combining
a plurality of sample sums selected from sample sums corresponding to image points
occurring in said horizontal image line containing said image point under examination
and a succeeding horizontal image line, wherein alternate sample sums from a horizontal
image line are combined in opposite polarity sense and one half of said plurality
of sample sums are combined in a positive polarity sense and one half in a negative
polarity sense to produce a second combined samples sums; and
means (98,100,102) coupled to said first and second means for combining sample
sums, for producing a chrominance motion indicating signal whenever said first and
second combined sample sums concurrently exceed a predeteremined magnitude.
14. A detector according to Claim 13 further comprising means (16) responsive to said
chrominance motion indicating signal and said fine detail luminance motion signal
for producing an image motion indicating signal whenever either said chrominance or
luminance motion signals indicate motion.
1. Un détecteur de mouvement interimages d'un signal comprenant :
une borne d'entrée (CV) pour recevoir un signal vidéo ; et
un moyen (10, 20) couplé à la borne d'entrée pour produire des différences entre
les signaux vidéo de périodes d'images successives;
caractérisé par une premier moyen (30), couplé audit moyen produisant des différences,
pour additionner un certain nombre desdites différences, ce certain nombre de différences
comprenant une différence correspondant à un point d'image actuellement sous examen
pour mouvement interimages et des différences correspondant à des points d'image à
proximité du point d'image sous examen se produisant dans une ligne d'image horizontale
contenant ledit point d'image sous examen et dans une ligne d'image horizontale précédente
pour produire des premières différences additionnées ;
un second moyen (34), couplé audit moyen pour produire des différences, pour additionner
un certain nombre desdites différences, ledit certain nombre de différences comprenant
une différence correspondant à un point d'image sous examen, et des différences correspondant
à des points d'image à proximité du point d'image sous examen se produisant dans la
ligne d'image horizontale contenant ledit point d'image sous examen et dans une ligne
d'image horizontale successive pour produire des secondes différences additionnées
; et
un moyen (32, 36, 38), couplé aux premier et second moyens d'addition, pour produire
un signal de mouvement chaque fois que des premières différences additionnées excèdent
concurremment une valeur de grandeur prédéterminée.
2. Un détecteur selon la revendication 1 pour détecter un mouvement interimages dans
des images représentées par un signal vidéo composé où :
la borne d'entrée (CV) est destinée à recevoir le signal vidéo composé (CV) ;
le moyen de production (10, 20) comprend un moyen à retard (10), couplé à la borne
d'entrée, pour produire des reproductions du signal vidéo composé retardé par un nombre
entier, comprenant un, de périodes d'image et un moyen (20) couplé à la borne d'entrée
et au moyen à retard pour produire des différences du signal vidéo composé et du signal
vidéo composé retardé ;
et comprenant de plus un moyen (24), comprenant un moyen couplé au moyen de production
(20) , pour laisser passer à une première borne de sortie des différences ayant des
composantes de fréquence normalement occupées par des composantes de chrominance du
signal vidéo composé à l'exclusion relative d'autres composantes de fréquence du signal
vidéo composé ;
et où des premier et second moyens (30, 34) sont couplés à la première borne de
sortie ;
et le moyen de production de signal de mouvement comprend un premier détecteur
de seuil (32), couplé au premier moyen, pour produire un signal d'indication de mouvement
lorsque des différences additionnées appliquées à celui-ci excèdent une grandeur prédéterminée,
un second détecteur de seuil (36), couplé au second moyen pour produire un signal
d'indication de mouvement lorsque des différences additionnées appliquées à celui-ci
excèdent une grandeur prédéterminée, et
un moyen (38, 84), couplé aux premier et second détecteurs de seuil pour produire
à une seconde borne de sortie, un signal d'indication de mouvement chaque fois que
les premier et second détecteurs de seuil produisent concurremment des signaux d'indication
de mouvement.
3. Un détecteur selon la revendication 2 qui comprend de plus :
un moyen (22) , couplé au moyen précité (20) pour produire des différences, pour
laisser passer à une troisième borne de sortie des différences ayant des composantes
de fréquence du signal vidéo composé ne se produisant pas normalement dans le spectre
de fréquences occupé par la composante de chrominance précitée ;
un troisième moyen (26, 56 62), couplé à la troisième borne de sortie, pour additionner
un certain nombre desdites différences, le certain nombre des différences correspondant
à des points d'image disposés symétriquement au point d'image précité sous examen
;
un troisième détecteur de seuil (28, 64), couplé au troisième moyen pour produire
un signal d'indication de mouvement lorsque des différences additionnées appliquées
à celui-ci excèdent une grandeur prédéterminée ; et
un moyen (40, 86) couplé au troisième détecteur de seuil et à la seconde borne
de sortie pour produire à une quatrième borne de sortie un signal d'indication de
mouvement chaque fois que le troisième détecteur de seuil ou la seconde borne de sortie
produit un signal d'indication de mouvement.
4. Un détecteur selon la revendication 3 où les différences précitées se produisent comme
différences de données échantillonnées et le troisième moyen précité (26) comprend
:
une connexion en cascade
d'un moyen (56) pour additonner un certain nombre de différences d'échantillons
correspondant aux points d'image se produisant dans une ligne d'image horizontale
et
d'un moyen (62) pour additionner les différences d'échantillons additionnées correspondant
aux points d'image se produisent dans des lignes d'images horizontales successives.
5. Un détecteur selon l'une des revendications 2 à 4 où les différences précitées se
produisent comme différences de données échantillonnées et le premier moyen précité
(30) comprend :
un premier moyen d'addition (70) couplé à la première borne de sortie précitée
pour additionner des échantillons de différence correspondant à des points d'image
se produisant dans la même ligne d'images horizontale ; et
un second moyen d'addition (78) couplé au premier d'addition, pour additionner
des échantillons de différences additionnées produites par le premier moyen d'addition
à partir de deux lignes d'images horizontales différentes ; et
où le second moyen précité (34) comprend un moyen (76) couplé au premier moyen
d'addition (70) pour additionner des échantillons de différences additionnées produits
par le premier moyen d'addition à partir de deux lignes d'images horizontales dont
l'une est différente des lignes d'images horizontales additionnées par le second moyen
d'addition.
6. Un détecteur selon l'une des revendications 2 à 5 comprenant de plus :
un moyen (90) couplé à la première borne d'entrée précitée et au moyen à retard
précité (10) pour produire des sommes du signal vidéo composé et du signal vidéo composé
retardé précités ;
un moyen de filtrage (92), couplé au moyen (90) pour produire des sommes pour laisser
passer les composantes de fréquence desdites sommes se produisant normalement dans
la bande de fréquences du signal vidéo composé occupée par les composantes de chrominance
;
un premier moyen additionnel (94, 114, 122), couplé au moyen de filtrage (92) pour
additionner un certain nombre, pair en nombre desdites sommes, le certain nombre de
sommes correspondant aux points d'image se produisant dans une ligne horizontale contenant
le point d'image sous examen et des points d'image se produisant dans une ligne d'image
horizontale précédant la ligne d'image horizontale contenant le point d'image sous
examen, le premier moyen additionnel (94, 114, 122) additionnant des sommes alternées
le long d'une ligne d'image horizontale de polarité opposée et où une moitié dudit
certain nombre de sommes a un sens de polarité positif et une moitié dudit certain
nombre de sommes a un sens de polarité négative ;
un premier détecteur de seuil additionnel (98), couplé au premier moyen additionnel
(94, 114, 122) pour produire un signal d'indication de mouvement chaque fois que des
signaux additionnés produits par le premier moyen de combinaison excèdent une grandeur
prédéterminée;
un second moyen additionnel (96, 114, 120), couplé au moyen de filtrage (92), pour
additionner un certain nombre pair en nombre, desdites sommes, ledit certain nombre
de sommes correspondant à des points d'image se produisant dans une ligne horizontale
contenant le point d'image sous examen et des points d'image se produisant dans une
ligne d'image horizontale suivant la ligne d'image horizontale contenant le point
d'image sous examen, le second moyen additionnel (96, 114, 120) additionnant des sommes
alternées le long d'une ligne d'image horizontale de polarité opposée et où une moitié
dudit certain nombre de sommes est additionnée dans un sens de polarité positive et
une moitié de la somme des polarités est additionnée dans un sens de polarité négative
;
un second détecteur de seuil additionnel (100), couplé au second moyen additionnel
(96, 114, 120) pour produire un signal d'indication de mouvement chaque fois que des
signaux additionnés produits par le second moyen additionnel excèdent une grandeur
prédéterminée ;
un moyen (102) couplé aux premier et second détecteurs de seuil additionnels pour
produire un signal d'indication de mouvement de chrominance lorsque les premier et
second détecteurs de seuil additionnels produisent concurremment des signaux d'indication
de mouvement.
7. Un détecteur selon la revendication 6 qui comprend de plus un moyen (16) répondant
au signal d'indication de mouvement de chrominance précité et au signal d'indication
de mouvement précité produits par la seconde borne de sortie précitée pour produire
un signal d'indication de mouvement à l'apparition du signal d'indication de mouvement
de chrominance ou du signal d'indication de mouvement produit à la seconde borne de
sortie.
8. Un détecteur selon la revendication 6 ou la revendication 7 où les sommes précitées
se produisent comme sommes de données échantillonnées et le premier moyen additionnel
(94) précité comprend :
une connexion en cascade de premier et second éléments à retard (110, 112) couplée
au filtre précité (92) pour produire des reproductions retardées desdites sommes les
premier et second éléments à retard produisant chacun des retards identiques d'un
nombre entier de périodes d'échantillon ;
un moyen (114) couplé au filtre (92) et au second élément à retard (112) pour additionner
des échantillons de somme dudit filtre et retarder de deux fois des échantillons de
somme du second élément à retard de sens de polarité opposé avec des échantillons
de somme retardés une fois du premier élément à retard (110) pour produire des échantillons
de somme additionnés horizontalement ;
un autre moyen à retard (118) couplé au moyen (114) pour produire des échantillons
de somme additionnés horizontalement, ledit autre moyen à retard (118) produisant
des retards d'échantillon d'une période de ligne d'image horizontale ; et
un autre moyen (122) couplé à une entrée et une sortie de l'autre moyen à retard
(118) pour additionner lesdits échantillons de somme additionnés horizontalement de
polarité opposée.
9. Un détecteur selon l'une des revendications 6 à 8 dans lequel la ligne d'image horizontale
précédente précitée est choisie de telle sorte que les composantes de chrominance
dans celle-ci ont une relation en opposition de phase avec les composantes de chrominance
correspondant à la ligne d'image horizontale précitée contenant le point d'image précité
sous examen.
10. Un détecteur selon la revendication 1 pour détecter un déplacement interimages du
signal composé, où la borne d'entrée est destinée à recevoir le signal vidéo composé
(CV) ;
le moyen de production (20, 24) produit les différences précitée comme échantillons
de différence interimages de signaux correspondants à partir de deux périodes d'images
des composantes de fréquence du signal vidéo composé contenant l'information de détail
d'image de luminance fin ;
et le moyen de production du signal de mouvement (32, 36, 38) est couplé aux premier
et second moyens de combinaison précités pour produire un signal de mouvement de luminance
de détail fin chaque fois que les premier et second échantillons de différence à additionner
excèdent concurremment une valeur de grandeur prédéterminée.
11. Un détecteur selon la revendication 10 comprenant de plus
un moyen (20, 22) couplé à la borne d'entrée précitée pour produire des échantillons
de différences inter images à partir des composantes de fréquence du signal vidéo
composé représentant l'information de détail d'image de luminance grossier ;
un troisième moyen (26) pour additionner un certain nombre d'échantillons de différence
représentant l'information de détail de luminance grossier pour produire des troisièmes
échantillons de différence additionnés, ledit certain nombre d'échantillons de différence
représentant une information de détail de luminance grossier correspondant à des points
d'image à proximité du point d'image précité sous examen ; et
un moyen (28) couplé au troisième moyen pour produire un signal d'indication de
mouvement de luminance de détail grossier chaque fois que les troisièmes échantillons
de différence additionnés dépassent une grandeur prédéterminée.
12. Un détecteur selon la revendication 11 comprenant de plus un moyen (40) répondant
au signal d'indication de mouvement de luminance de détail fin et au signal d'indication
de mouvement de luminance de détail grossier pour produire un signal d'indication
de mouvement de luminance chaque fois que soit le signal d'indication de mouvement
de luminance de détail fin, soit le signal d'indication de mouvement de luminance
de détail grossier indique un mouvement.
13. Un détecteur selon l'une des revendications 10 à 12 comprenant de plus
un moyen (90, 92) couplé à la borne d'entrée précitée pour produire des sommes
d'échantillons interimages des signaux correspondants à partir de deux périodes d'images
à partir de composantes de fréquence du signal vidéo composé contenant des composantes
de chrominance à l'exclusion substantielle d'autres composantes de fréquence du signal
vidéo composé ;
un premier moyen (94) couplé au moyen pour produire les sommes d'échantillons pour
combiner un certain nombre des sommes d'échantillons choisies à partir des sommes
d'échantillons correspondant aux points d'image se produisant dans la ligne d'image
horizontale précitée contenant le point d'image précité sous examen et une ligne d'image
horizontale précédente où des sommes d'échantillons alternés d'une ligne d'image horizontale
sont combinées en sens de polarités opposés et une moitié dudit certain nombre de
sommes d'échantillons est combinée dans un sens de polarité positive et une moitié
dans un sens de polarité négative pour produire des premières sommes d'échantillons
combinées ; et
un second moyen (96) couplé au moyen pour produire des sommes d'échantillons pour
combiner un certain nombre de sommes d'échantillons choisies à partir des sommes d'échantillons
correspondant aux points d'image se produisant dans la ligne d'image horizontale contenant
le point d'image sous examen et une ligne d'image horizontale suivante où des sommes
d'échantillons alternées d'une ligne d'image horizontale sont combinées en sens de
polarités opposés et une moitié dudit certain nombre de sommes d'échantillons est
combinée dans un sens de polarité positive et une moitié dans un sens de polarité
négative pour produire des secondes sommes d'échantillons combinées ; et
un moyen (98, 100, 102) couplé aux premier et second moyens pour combiner des sommes
d'échantillons pour produire un signal d'indication de mouvement de chrominance chaque
lois que les première et seconde sommes d'échantillons combinées excèdent concurremment
une grandeur prédéterminée.
14. Un détecteur selon la revendication 13 comprenant de plus un moyen (16) répondant
au signal d'indication de mouvement de chrominance et au signal de mouvement de luminance
de détail fin pour produire un signal d'indication de mouvement d'image chaque fois
que le signal de mouvement de chrominance ou de luminance indique un mouvement.
1. Detektor für Bewegungen von Bild zu Bild in einem Signal,
mit einer Eingangsklemme (CV) zum Empfang eines Videosignals
und mit einer mit der Eingangsklemme gekoppelten Einrichtung (10, 20) zur Bildung
von Differenzen zwischen Videosignalen aus aufeinanderfolgenden Bildperioden,
gekennzeichnet durch:
eine mit der Einrichtung zur Bildung von Differenzen gekoppelte Einrichtung (30)
zur Summierung einer Mehrzahl der Differenzen, wobei diese Mehrzahl eine Differenz
enthält, die einem Bildpunkt zugeordnet ist, der gerade auf Bewegung von Bild zu Bild
geprüft wird, und Differenzen, die Bildpunken zugeordnet sind, welche sich in der
Nähe des unter Prüfung stehenden Bildpunktes befinden und in einer den unter Prüfung
stehenden Bildunkt enthaltenden horizontalen Bildzeile und in einer vorangehenden
horizontalen Bildzeile liegen, um erste summierte Differenzen zu erzeugen;
eine mit der Einrichtung zur Bildung von Differenzen gekoppelte zweite Einrichtung
(34) zur Summierung einer Mehrzahl der Differenzen, wobei diese Mehrzahl eine Differenz
enthält, die dem unter Prüfung stehenden Bildpunkt zugeordnet ist, und Differenzen,
die Bildpunkten zugeordnet sind, welche sich in der Nähe des unter Prüfung stehenden
Bildpunktes befinden und in der den unter Prüfung stehenden Bildplunkt enthaltenden
horizontalen Bildzeile und in einer nachfolgenden horizontalen Bildzeile liegen, um
zweite summierte Differenzen zu erzeugen, und
eine mit der ersten und der zweiten summierenden Einrichtung gekoppelte Einrichtung
(32, 36, 38) zur Erzeugung eines Bewegungssignals immer dann, wenn die ersten und
die zweiten summierten Differenzen gleichzeitig einen vorbestimmten Betragswert überschreiten.
2. Detektor nach Anspruch 1 zur Erfassung von Bild-zu-Bild-Bewegung in Bildern, die durch
ein Videosignalgemisch dargestellt werden, wobei:
die Eingangsklemme (CV) zum Empfang des Videosignalgemischs (CV) vorgesehen ist;
die differenzbildende Einrichtung (10, 20) eine mit der Eingangsklemme gekoppelte
Verzögerungseinrichtung (10) aufweist, um Nachbildungen des Videosignalgemischs zu
liefern, die um eine ganze Zahl, einschließlich eins, von Bildperioden verzögert sind,
und eine mit der Eingangsklemme der Verzögerungseinrichtung gekoppelte Einrichtung
(20) zur Bildung von Differenzen zwischen dem Videosignalgemisch und dem verzögerten
Videosignalgemisch; ferner eine Einrichtung (24) vorgesehen ist, die mit der differenzbildenden
Einrichtung (20) gekoppelt ist, um an einer ersten Ausgangsklemme Differenzen mit
Frequenzkomponenten durchzulassen, die normalerweise von Farbartkomponenten des Videosignalgemischs
belegt werden, unter relativem Ausschluß anderer Frequenzkomponenten des Videosignalgemischs,
und wobei die besagte erste und zweite Einrichtung (30, 34) mit der besagten ersten
Ausgangsklemme gekoppelt sind
und die das Bewegungssignal erzeugende Einrichtung folgendes aufweist: einen ersten
Schwellendetektor (32), der mit der ersten Einrichtung gekoppelt ist, um ein bewegungsanzeigendes
Signal zu erzeugen, wenn ihm angelegte summierte Differenzen einen vorbestimmten Betrag
überschreiten,
einen zweiten Schwellendetektor (36), der mit der zweiten Einrichtung gekoppelt
ist, um ein bewegungsanzeigendes Signal zu erzeugen, wenn ihm angelegte summierte
Differenzen einen vorbestimmten Betrag übersteigen, und eine Einrichtung (38, 84),
die mit dem ersten und dem zweiten Schwellendetektor gekoppelt ist, um an einer zweiten
Ausgangsklemme ein bewegungsanzeigendes Signal immer dann zu erzeugen, wenn der erste
und der zweite Schwellendetektor gleichzeitig bewegungsanzeigende Signale erzeugen.
3. Detektor nach Anspruch 2, der ferner folgendes enthält:
eine Einrichtung (22), die mit der differenzbildenden Einrichtung (20) gekoppelt
ist, um an einer dritten Ausgangsklemme Differenzen durchzulassen, welche Frequenzkomponenten
des Videosignalgemischs enthalten, die normalerweise nicht in dem von der Farbartkomponente
belegten Frequenzspektrum vorkommen;
eine dritte Einrichtung (26, 56, 62), die mit der dritten Ausgangsklemme gekoppelt
ist, um eine Mehrzahl der Differenzen zu summieren, wobei diese Mehrzahl Bildpunkten
zugeordnet ist, die symmetrisch bezüglich des unter Prüfung stehenden Bildpunktes
liegen;
einen dritten Schwellendetektor (28, 64), der mit der dritten Einrichtung gekoppelt
ist, um ein bewegungsanzeigendes Signal zu erzeugen, wenn ihm angelegte summierte
Differenzen einen vorbestimmten Betrag übersteigen, und
eine Einrichtung (40, 86), die mit dem dritten Schwellendetektor und mit der zweiten
Ausgangsklemme gekoppelt ist, um an einer vierten Ausgangsklemme ein bewegungsanzeigendes
Signal immer dann zu erzeugen, wenn der dritte Schwellendetektor oder die zweite Ausgangsklemme
ein bewegungsanzeigendes Signal liefert.
4. Detektor nach Anspruch 3, wobei die Differenzen als Differenzen von Datenabtastwerten
erscheinen und die dritte Einrichtung (26) folgendes aufweist:
eine Kaskadenschaltung aus
einer Einrichtung (56) zur Summierung einer Mehrzahl von Abtastwert-Differenzen,
die Bildpunkten zugeordnet sind, welche in ein und derselben horizontalen Bildzeile
liegen, und
eine Einrichtung (62) zur Summierung summierter Abtastwert-Differenzen, die Bildpunkten
zugeordnet sind, die in aufeinanderfolgenden horizontalen Bildzeilen liegen.
5. Detektor nach einem der Ansprüche 2 bis 4, wobei die Differenzen als Differenzen von
Datenabtastwerten erscheinen und die erste Einrichtung (30) folgendes enthält:
eine mit der ersten Ausgangsklemme gekoppelte erste Summierungseinrichtung (70)
zur Summierung von Differenz-Abtastwerten, die Bildpunkten entsprechen, welche in
ein und derselben horizontalen Bildzeile liegen, und
eine mit der ersten Summierungseinrichtung gekoppelte zweite Summierungseinrichtung
(78) zur Summierung summierter Differenz-Abtastwerte, die von der ersten Summierungseinrichtung
aus zwei verschiedenen horizontalen Bildzeilen geliefert werden, und
wobei die zweite Einrichtung (34) eine mit der ersten Summierungseinrichtung (70)
gekoppelte Einrichtung (76) enthält, um summierte Differenz-Abtastwerte zu summieren,
die von der ersten Summierungseinrichtung aus zwei horizontalen Bildzeilen geliefert
werden, von denen eine eine andere als diejenigen horizontalen Bildzeilen ist, die
von der zweiten Summierungseinrichtung summiert werden.
6. Detektor nach einem der Ansprüche 2 bis 5, ferner enthaltend:
eine Einrichtung (90), die mit der Eingangsklemme und mit der Verzögerungseinrichtung
(10) gekoppelt ist, um Summen des Videosignalgemischs und des verzögerten Videosignalgemischs
zu bilden;
eine Filtereinrichtung (92), die mit der summenbildenden Einrichtung (90) gekoppelt
ist, um solche Frequenzkomponenten der Summen durchzulassen, die normalerweise in
dem von Farbartkomponenten belegten Frequenzband des Videosignalgemischs vorkommen;
eine erste zusätzliche Einrichtung (94, 114, 122), die mit der Filtereinrichtung
(92) gekoppelt ist, um eine geradzahlige Mehrzahl der Summen durchzulassen, wobei
diese Mehrzahl der Summen Bildpunkten zugeordnet ist, welche in einer den unter Prüfung
stehenden Bildpunkt enthaltenden Horizontalzeile vorkommen, und Bildpunkte, welche
in einer horizontalen Bildzeile vorkommen, die der den unter Prüfung stehenden Bildunkt
enthaltenden horizontalen Bildzeile vorangehen, wobei die erste zusätzliche Einrichtung
(94, 114, 122) abwechselnde Summen entlang einer horizontalen Bildzeile in entgegengesetzter
Polarität miteinander addiert und wobei eine Hälfte der besagten Mehrzahl von Summen
einen positiven Polaritätssinn und eine Hälfte der Mehrzahl von Summen einen negativen
Polaritätssinn hat;
einen ersten zusätzlichen Schwellendetektor (98), der mit der ersten zusätzlichen
Einrichtung (94, 114, 122) gekoppelt ist, um ein bewegungsanzeigendes Signal immer
dann zu erzeugen, wenn summierte Signale, die von der ersten Kombiniereinrichtung
geliefert werden, einen vorbestimmten Betrag übersteigen;
eine zweite zusätzliche Einrichtung (96, 114, 120), die mit der Filtereinrichtung
(92) gekoppelt ist, um eine geradzahlige Mehrzahl der Summen zu summieren, wobei diese
Mehrzahl von Summen Bildpunkten zugeordnet ist, die in der den unter Prüfung stehenden
Bildpunkt enthaltenden Horizontalzeile liegen, und Bildpunkten, die in einer horizontalen
Bildzeile liegen, welche der den unter Prüfung stehenden Bildpunkt enthaltenden horizontalen
Bildzeile folgt, wobei die zweite zusätzliche Einrichtung (96, 114, 120) abwechselnde
Summen entlang einer horizontalen Bildzeile in entgegengesetzter Polarität miteinander
summiert und wobei eine Hälfte der Mehrzahl von Summen in einem positiven Polaritätssinn
und eine Hälfte der Mehrzahl von Summen in einem negativen Polaritätssinn addiert
werden;
einen zweiten zusätzlichen Schwellendetektor (100), der mit der zweiten zusätzlichen
Einrichtung (96, 114, 120) gekoppelt ist, um ein bewegungsanzeigendes Signal immer
dann zu erzeugen, wenn summierte Signale, die von der zweiten zusätzlichen Einrichtung
geliefert werden, einen vorbestimmten Betrag überschreiten;
eine Einrichtung (102), die mit dem ersten und mit dem zweiten zusätzlichen Schwellendetektor
gekoppelt ist, um ein Bewegung in der Farbart anzeigendes Signal immer dann zu erzeugen,
wenn der erste und der zweite zusätzliche Schwellendetektor gleichzeitig bewegungsanzeigende
Signale liefern.
7. Detektor nach Anspruch 6, der ferner eine Einrichtung (16) enthält, die auf das eine
Bewegung in der Farbart anzeigende Signal und auf das von der zweiten Ausgangsklemme
gelieferte bewegungsanzeigende Signal anspricht, um ein bewegungsanzeigendes Signal
zu liefern, wenn das eine Farbartbewegung anzeigende Signal oder das an der zweiten
Ausgangsklemme gelieferte bewegungsanzeigende Signal erscheint.
8. Detektor nach Anspruch 6 oder 7, wobei die Summen in Form von Datenabtastwerten erscheinen
und die erste zusätzliche Einrichtung (94) folgendes enthält:
eine mit dem Filter (92) gekoppelte Kaskadenschaltung aus einem ersten und einem
zweiten Verzögerungselement (110, 112) zur Lieferung verzögerter Nachbildungen der
besagten Summen, wobei jedes der ersten und zweiten Verzögerungselemente die gleiche
Verzögerung entsprechend einer ganzen Zahl von Abtastperioden bringt;
eine Einrichtung (114), die mit dem Filter (92) und mit dem zweiten Verzögerungselement
(112) gekoppelt ist, um die Summen-Abtastwerte vom Filter und zweimal verzögerte Summen-Abtastwerte
vom zweiten Verzögerungselement in entgegengesetztem Polaritätssinn mit einmal verzögerten
Summen-Abtastwerten vom ersten Verzögerungselement (110) zu summieren und damit horizontal-summierte
Summen-Abtastwerte zu erzeugen;
eine weitere Verzögerungseinrichtung (118), die mit der Einrichtung (114) zur Erzeugung
horizontal-summierter Summen-Abtastwerte gekoppelt ist und Abtastwertverzögerungen
entsprechend einer Horizontalbildzeilenperiode bringt, und
eine weitere Einrichtung (122), die mit einem Eingang und einem Ausgang der weiteren
Verzögerungseinrichtung (118) gekoppelt ist, um die horizontal-summierten Summen-Abtastwerte
in entgegengesetzter Polarität zu summieren.
9. Detektor nach einem der Ansprüche 6 bis 8, worin die besagte vorangehende horizontale
Bildzeile so ausgewählt ist, daß darin enthaltene Farbartkomponenten in Gegenphase
zu Farbartkomponenten sind, die derjenigen horizontalen Bildzeile entsprechen, welche
den unter Prüfung stehenden Bildpunkt enthält.
10. Detektor nach Anspruch 1 zur Erfassung einer Bild-zu-Bild-Bewegung in einem Signalgemisch,
wobei die Eingangsklemme zum Empfang des Videosignalgemischs (CV) vorgesehen ist,
die differenzbildende Einrichtung (20, 24) die Differenzen als Abtastwerte von
Bild-zu-Bild-Differenzen zwischen einander entsprechenden Signalen aus zwei Bildperioden
unter Verwendung derjenigen Frequenzkomponenten des Videosignalgemischs bildet, die
Leuchtdichteinformation feiner Bilddetails enthalten,
und die das Bewegungssignal erzeugende Einrichtung (32, 36, 38) mit der ersten
und der zweiten Kombiniereinrichtung gekoppelt ist, um ein Leuchtdichtefeindetail-Bewegungssignal
immer dann zu erzeugen, wenn die ersten und die zweiten summierten Differenz-Abtastwerte
gleichzeitig einen vorbestimmten Betragswert überschreiten.
11. Detektor nach Anspruch 10, ferner aufweisend:
eine Einrichtung (20, 22), die mit der Eingangsklemme gekoppelt ist, um Abtastwerte
von Bild-zu-Bild-Differenzen aus Frequenzkomponenten des Videosignalgemischs zu erzeugen,
die Bildinformation grober Leuchtdichtedetails darstellen;
eine dritte Einrichtung (26) zur Summierung einer Vielzahl von Differenz-Abtastwerten,
welche Information grober Leuchtdichtedetails darstellen, um dritte summierte Differenz-Abtastwerte
zu erzeugen, wobei die Vielzahl von Differenz-Abtastwerten, welche Information grober
Leuchtdichtedetails darstellen, Bildpunkten entsprechen, die nahe dem unter Prüfung
stehenden Bildpunkt liegen, und
eine mit der dritten Einrichtung gekoppelte Einrichtung (28) zur Erzeugung eines
Leuchtdichtegrobdetail-Bewegungsanzeigesignals immer dann, wenn die dritten summierten
Differenz-Abtastwerte einen vorbestimmten Betrag überschreiten.
12. Detektor nach Anspruch 11, der ferner eine auf das Leuchtdichtefeindetail-Bewegungsanzeigesignal
und auf das Leuchtdichtegrobdetail-Bewegungsanzeigesignal anspricht, um ein Leuchtdichtebewegungs-Anzeigesignal
immer dann zu entwickeln, wenn entweder das Leuchtdichtefeindetail- oder das Leuchtdichtegrobdetail-Bewegungsanzeigesignal
eine Bewegung anzeigt.
13. Detektor nach einem der Ansprüche 10 bis 12, ferner aufweisend:
eine mit der Eingangsklemme gekoppelte Einrichtung (90, 92) zur Erzeugung von Bild-zu-Bild-Abtastwertsummen
einander entsprechender Signale aus zwei Bildperioden unter Verwendung von Frequenzkomponenten
des Videosignalgemischs, die Farbartkomponenten praktisch unter Ausschluß anderer
Frequenzkomponenten des Videosignalgemischs enthalten;
eine mit der Einrichtung zur Erzeugung der Abtastwertsummen gekoppelte erste Einrichtung
(94) zum Kombinieren einer Mehrzahl von Abtastwertsummen, die aus Abtastwertsummen
ausgewählt sind, welche Bildpunkten entsprechen, die in der den unter Prüfung stehenden
Bildpunkt enthaltenden horizontalen Bildzeile und in einer vorangehenden horizontalen
Bildzeile liegen, wobei abwechselnde Abtastwertsummen aus einer horizontalen Bildzeile
in entgegengesetztem Polaritätssinn kombiniert werden und eine Hälfte der Mehrzahl
von Abtastwertsummen in einem positiven Polaritätssinn kombiniert wird und eine Hälfte
in einem negativen Polaritätssinn kombiniert wird, um erste kombinierte Abtastwertsummen
zu erzeugen;
eine zweite Einrichtung (96), die mit der Einrichtung zur Erzeugung von Abtastwertsummen
gekoppelt ist, um eine Vielzahl von Abtastwertsummen zu kombinieren, die aus Abtastwertsummen
ausgewählt sind, welche Bildpunkten entsprechen, die in der den unter Prüfung stehenden
Bildpunkt enthaltenden horizontalen Bildzeile und in einer nachfolgenden horizontalen
Bildzeile liegen, wobei abwechselnde Abtastwertsummen aus einer horizontalen Bildzeile
in entgegengesetztem Polaritätssinn kombiniert werden und eine Hälfte der Mehrzahl
von Abtastwertsummen in einem positiven Polaritätssinn und eine Hälfte in einem negativen
Polaritätssinn kombiniert werden, um zweite kombinierte Abtastwertsummen zu erzeugen,
und
eine mit der ersten und der zweiten Einrichtung zum Kombinieren von Abtastwertsummen
gekoppelte Einrichtung (98, 100, 102) zur Erzeugung eines Farbart-Bewegungsanzeigesignals
immer dann, wenn die ersten und die zweiten kombinierten Abtastwertsummen gleichzeitig
einen vorbestimmten Betrag überschreiten.
14. Detektor nach Anspruch 13, ferner enthaltend eine Einrichtung (16), die auf das Farbart-Bewegungsanzeigesignal
und auf das Leuchtdichtefeindetail-Bewegungssignal anspricht, um ein Bildbewegungs-Anzeigesignal
immer dann zu erzeugen, wenn entweder das Farbart- oder das Leuchtdichte-Bewegungsanzeigesignal
Bewegung anzeigt.